Hello, I've been looking in getting the MyBook Live Duo's USB OTG port to function. The SoC is a APM82181. Which has a PowerPC 464 core and related to the supported canyonlands architecture in arch/powerpc/.
Currently in -next the dwc2 module doesn't load: dwc2 4bff80000.usbotg: dwc2_core_reset() HANG! AHB Idle GRSTCTL=80 dwc2 4bff80000.usbotg: Bad value for GSNPSID: 0x0a29544f Looking at the Bad GSNPSID value: 0x0a29544f. It is obvious that this is an endian problem. git finds this patch: commit 95c8bc3609440af5e4a4f760b8680caea7424396 Author: Antti Seppälä <a.sepp...@gmail.com> Date: Thu Aug 20 21:41:07 2015 +0300 usb: dwc2: Use platform endianness when accessing registers This patch is necessary to access dwc2 registers correctly on big-endian systems such as the mips based SoCs made by Lantiq. Then dwc2 can be used to replace ifx-hcd driver for Lantiq platforms found e.g. in OpenWrt. The patch was autogenerated with the following commands: $EDITOR core.h sed -i "s/\<readl\>/dwc2_readl/g" *.c hcd.h hw.h sed -i "s/\<writel\>/dwc2_writel/g" *.c hcd.h hw.h Some files were then hand-edited to fix checkpatch.pl warnings about too long lines. which unfortunately, broke the USB-OTG port on the MyBook Live Duo. Reverting to the readl / writel: --- diff --git a/drivers/usb/dwc2/core.h b/drivers/usb/dwc2/core.h index 3c58d63..c021c1f 100644 --- a/drivers/usb/dwc2/core.h +++ b/drivers/usb/dwc2/core.h @@ -66,7 +66,7 @@ static inline u32 dwc2_readl(const void __iomem *addr) { - u32 value = __raw_readl(addr); + u32 value = readl(addr); /* In order to preserve endianness __raw_* operation is used. Therefore * a barrier is needed to ensure IO access is not re-ordered across @@ -78,7 +78,7 @@ static inline u32 dwc2_readl(const void __iomem *addr) static inline void dwc2_writel(u32 value, void __iomem *addr) { - __raw_writel(value, addr); + writel(value, addr); /* * In order to preserve endianness __raw_* operation is used. Therefore --- restores the dwc-otg port to full working order: dwc2 4bff80000.usbotg: Specified GNPTXFDEP=1024 > 256 dwc2 4bff80000.usbotg: EPs: 3, shared fifos, 2042 entries in SPRAM dwc2 4bff80000.usbotg: DWC OTG Controller dwc2 4bff80000.usbotg: new USB bus registered, assigned bus number 1 dwc2 4bff80000.usbotg: irq 33, io mem 0x00000000 hub 1-0:1.0: USB hub found hub 1-0:1.0: 1 port detected root@mbl:~# usb 1-1: new high-speed USB device number 2 using dwc2 So, what to do? Regards, Christian _______________________________________________ Linuxppc-dev mailing list Linuxppc-dev@lists.ozlabs.org https://lists.ozlabs.org/listinfo/linuxppc-dev